code: def _remove_slash(rule):
      if rule.startswith("\\"):
          return rule[1:]
      return rule
  
file_path: dvc/dvc/pathspec_math.py
imports: from collections import namedtuple
  from pathspec.util import normalize_file
  from dvc.utils import relpath
label_desc: Use image node_id 3 for calling a global function with example usage: _remove_slash(rule) and returns: rule, rule